LPS-32302 Use SystemException for technical errors and PortalException for logical errors
LPS-32302 Do not roll the transaction back, if the recipient does not have a private messaging portlet on his/her private page
LPS-32302 Initial refactor of getMessage()
LPS-32302 Refactor exception handling in the view/controller layer
LPS-32302 Validating attachments cannot be done here, because checkData() is called through XHR